GNSS receivers, such as global positioning system (GPS) receivers, receive and process multiple satellite positioning signals simultaneously. Frequently, GNSS receivers operate in the presence of interfering or jamming signals. Generally, when a spatial separation exists between the jamming signals and the desired signals, a spatial nulling array can be used to enhance signal reception.
Typically, a very large number of complex multiplies (i.e., multiplication of complex numbers) are required to implement a spatial nulling array. If the antenna array includes Ne antenna element inputs, and a set of weights corresponding to the tap values for one Nt tap finite impulse response (FIR) filter per element, the array will include Nt*Ne total taps per antenna pattern. To generate the output for one antenna pattern, the outputs of the Ne FIR filters corresponding to that one pattern are summed together. To generate one set of output samples for Np patterns, a total of Np*Nt*Ne complex multiplies are required. Consequently, digital implementations of spatial nulling arrays can consume considerable processing power.